docs: def complete(self, message, endpoint, return_to):
          """Process the OpenID message, using the specified endpoint
          and return_to URL as context. This method will handle any
          OpenID message that is sent to the return_to URL.
          """
          mode = message.getArg(OPENID_NS, 'mode', '<No mode set>')
  
          modeMethod = getattr(self, '_complete_' + mode,
                               self._completeInvalid)
  
          return modeMethod(message, endpoint, return_to)